Top seed Montana had no trouble reaching its second straight championship game, routing unseeded Northern Iowa, 38-0.
Furman (12-2) and Montana (14-1) will meet in the title contest Friday night in Chattanooga, Tenn. It will be their first meeting ever.
Furman is 1-1 in championship games, both against Georgia Southern. The Paladins captured their only title with a 17-12 victory over their Southern Conference rival in 1988.
Montana also split its previous title-game appearances. The Grizzlies beat Marshall, 22-20, in 1995 to claim their lone championship and lost to Georgia Southern, 27-25, last season.
On Saturday, Furman won at Georgia Southern (12-2) for the first time in six tries and avenged a 20-10 regular-season loss.
The Paladins held Adrian Peterson, the all-time leading rusher in Division I-AA history, to 68 yards on 18 carries in his final college game. It marked only the third time in 57 career games that Peterson had been held below 100 yards.
The longest run for Peterson, who finished with a 13-2 playoff mark, was just nine yards. He averaged 181 yards and scored 30 touchdowns in his previous 14 postseason contests.
It also was the final appearance at Georgia Southern for coach Paul Johnson, who posted a 62-10 record in his five years at the school. Johnson accepted the Navy job last Sunday.
The loss ended Georgia Southern's 27-game home playoff winning streak and overall 39-game home winning streak. The Golden Eagles also won consecutive titles in 1985-86 and 1989-90, but they have never won three in a row.
For the second straight game, Furman overcame the absence of leading rusher Louis Ivory, the Southern Conference Offensive Player of the Year who has been sidelined with a sprained left MCL.
Billy Napier completed all 12 passes for 159 yards for the Paladins, who overcame a 17-7 halftime deficit. Furman tied it on Napier's 21-yard touchdown pass to Bear Rinehart with 10:52 left in the third quarter and took a 24-17 lead on Eric Emerson's one-yard run with 8:24 remaining in the fourth.
Yo Humphery and quarterback John Edwards each rushed for two touchdowns and more than 100 yards for the Grizzlies, who improved to 4-0 all time against Northern Iowa (11-3).
Edwards, who rushed for 111 yards on just 13 carries, scored on runs of 12 and six yards in the first quarter as the Grizzlies opened a 17-0 lead.
Humphery complimented Edwards by gaining 142 yards on 22 attempts. He scored on an eight-yard run with 6:21 left in the second quarter to give Montana a 31-0 halftime lead, then added a three-yard touchdown run in the third period.
Northern Iowa, the only major surprise in the final four, dropped to 0-5 in semifinals games. The Panthers also lost in the semifinals in 1985, 1987, 1992 and 1996.